1. Field of the Invention
The invention relates to a method for operating active stabilizers in a motor vehicle and to a motor vehicle having active stabilizers.
Roll behavior of motor vehicles can be influenced by using active stabilizers. When there is an increased tendency of the vehicle body to roll, stabilizers can be used for coupling in a torque which acts counter to the roll tendency. For that purpose, the stabilizers on the axles are respectively separated in two parts and are connected to one another at their separated ends via an actuator.
When driving through a turn, the tilting or rolling motion of the vehicle body can be reduced by activating the stabilizers, i.e. by introducing a torsional moment between the separated ends. However, when driving straight ahead, the stabilizer is deactivated. Conventional stabilizer concepts however also provide for an effective connection between the separated ends via the actuators even in this situation. However in this case no additional torque is introduced.
The torque can be introduced both, with an electric actuator and with a hydraulic actuator. Examples for the introduction of torque are found in Published, Non-Prosecuted German Patent Application Nos. DE 196 29 582 A1, DE 198 36 674 A1, DE 102 10 306 A1, and DE 102 33 499 A1. This concept is also used in street vehicles for roll stabilization with the goal of avoiding an extreme articulation of the wheels of an axle. The main focus of the control is the leveling of the vehicle body and influencing the tendency of the vehicle to oversteer and understeer by alternately changing the rate of rolling at the vehicle axes in dependence of vehicle operation parameters such as the lateral acceleration.
European Patent Application No. EP 1 403 104 A2 and Published, Non-Prosecuted German Patent Application No. DE 101 57 085 A1 further disclose connecting the ends of a separated torsion bar stabilizer by a clutch, such that it is possible to switch back and forth between a coupled position and an uncoupled position. In the coupled position there is however no additional torque introduced into the mechanical system. In the uncoupled position the stabilizer is disabled. This concept is especially suited for off-road use, where allowing an increased articulation is desired. In this case this is achieved by uncoupling the stabilizer.
If a motor vehicle is to be tuned for on-road use as well as for off-road use, there is a target conflict with respect to the stabilization.